Responsive

To control an element's background color opacity at a specific breakpoint, add a {screen}: prefix to any existing background color opacity utility. For example, use md:bg-opacity-50 to apply the bg-opacity-50 utility at only medium screen sizes and above.

Disabling

If you don't plan to use the background opacity utilities in your project, you can disable them entirely by setting the backgroundOpacity property to false in the corePlugins section of your config file: